Pen needle hub having increased contact area

ABSTRACT

A pen needle assembly having a hub with an increased surface area that contacts a patient&#39;s skin is provided. The increased contact area of the hub with the patient&#39;s skin during injection of a cannula decreases the pressure exerted against the patient&#39;s skin, thereby increasing the comfort of the patient. A bonding adhesive is disposed on an outer surface of the hub, thereby decreasing the required curing time of the adhesive. Additionally, the increased contact area, between the cannula adhesive and hub increases the strength of the bond therebetween.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of Ser. No. 12/205,711,filed Sep. 5, 2008, which claims the benefit under 35 U.S.C. §119(e) ofprovisional application Ser. No. 60/935,951, filed Sep. 7, 2007, whichare hereby incorporated by reference in their entirety

FIELD OF THE INVENTION

The present invention relates generally to a hub for a pen needleassembly. More particularly, the present invention generally relates toa hub having an increased surface area that contacts a patient's skinduring an injection, thereby reducing the pressure exerted against theskin during the injection. Still more particularly, the presentinvention generally relates to a hub in which the cannula is bonded tothe hub by an adhesive disposed on an outer surface of the hub, therebyincreasing the strength of the bond, and which is applicable to anynumber of devices, such as syringes and other needle-containing devices,in which such features are desirable.

BACKGROUND OF THE INVENTION

Insulin and other injectable medications are commonly given with drugdelivery pens, whereby a disposable pen needle is attached to facilitatedrug container access and allow fluid egress from the container throughthe needle into the patient.

As technology and competition advance, driving the desire for shorter,thinner, less painful, and more efficacious injections, the design ofthe pen needle and parts thereof becomes more and more important.Designs need to proactively address ergonomically improving injectiontechnique, injection depth control and accuracy, the ability to besafely used and transported to disposal, and protection against misusewhile maintaining the ability to be economically manufactured on a massproduction scale.

Drug delivery pens, such as the existing drug delivery pen 100 shown inFIGS. 1 and 2, typically comprise a dose knob/button 24, an outer sleeve13, and a cap 21. The dose knob/button 24 allows a user to set thedosage of medication to be injected. The outer sleeve 13 is gripped bythe user when injecting medication. The cap 21 is used by the user tosecurely hold the pen injector device 100 in a shirt pocket, purse orother suitable location and provide cover/protection from accidentalneedle injury.

FIG. 2 is an exploded view of the pen needle assembly 100 of FIG. 1. Thedose knob/button 24 has a dual purpose and is used both to set thedosage of the medication to be injected and to inject the dosedmedicament via the lead screw 7 and stopper 15 through the medicamentcartridge 12 attached through the reservoir housing or hub 20. Instandard drug delivery pens the dosing and delivery mechanisms are allfound within the outer sleeve 13 and are not described in greater detailhere as they are understood by those knowledgeable of the prior art. Themedicament cartridge 12 is typically attached to a standard pen injectorhousing via known attachment means, such as ¼ turn fastening features.The distal movement of the plunger or stopper 15 within the medicamentcartridge 12 causes medication to be forced into the reservoir housing20. The medicament cartridge 12 is sealed by septum 16, which ispunctured by a septum penetrating needle cannula (not shown) locatedwithin reservoir housing 20. Reservoir housing 20 is preferably screwedonto the medicament cartridge 12, although other attachment means can beused. To protect the patient needle 11, an outer shield 69 attaches tothe pen needle assembly 9. An inner shield 59 covers the patient needle11 within the outer shield 69. The cap 21 fits snugly against outersleeve 13 to allow a user to securely carry the drug delivery pen 100.

Another existing pen needle assembly 2 is shown in FIG. 3. The needleassembly 2 includes a cover 101, an inner shield 200, a needle cannula300, and a needle hub 400. A proximal end 310 of the needle cannula 300is inserted into a center opening in the distal (patient) end 405 of theneedle hub 400 until a predetermined length of the distal end 305 of theneedle cannula 300 remains extended. The needle cannula 300 is securedby epoxy or adhesive in the distal end 405 of the hub 400 within the hubprotrusion 420.

To protect users from injury and the needle cannula 300 from beingdamaged, the inner shield 200 covers the exposed portion of needlecannula 300. The open proximal end 210 of the inner shield 200 is placedover the exposed portion of needle cannula 300. The open proximal end110 of the cover 100 envelops the inner shield 200, needle cannula 300,and hub 400.

Distal end 105 of the cover 101 is closed to prevent contamination anddamage to the inner components of pen needle assembly 2, and to preventinjury to anyone who may handle it prior to use. The proximal end 410 ofthe hub 400 is typically covered by a sanitary cover (not shown) on end110 of cover 101. The pen needle assembly 2 is then ready for shipmentto a user. When the user is ready to use the pen needle assembly 2, thesanitary cover (not shown) is removed, the hub 400 is screwed onto astandard medication cartridge 12 (FIG. 2), and the cover 101 and innershield 200 are separately removed from the hub 400/cannula 300subassembly by a pulling action. The distal end 205 of the inner shield200 is closed to cover the distal end 305 of the needle cannula 300after the cover 101 is removed to protect the user from an accidentalstick. The inner shield 200 is then removed to access the needle cannula300. Thus, two separate pulling actions are required to remove both thecover 101 and the inner shield 200.

FIG. 4 is a cross-sectional view of a pen needle assembly in theconfiguration that it would be received by a user (with a sanitary covernot shown). An inner shield 470 covers a needle cannula 430.Additionally, the hub 460 includes a center hub protrusion 465. The skincontact plane 450 is the plane of the straight surface across the distalend of the center hub protrusion 465.

A protrusion 520, in which the cannula is bonded, extending from the hub500 of existing pen needle assemblies is typically narrow, as shown inFIG. 5. The small surface area 530 provided at the distal end of anarrow hub protrusion 520 results in a high pressure being exertedagainst a patient's skin during injection of the cannula, therebyincreasing discomfort of the patient.

Furthermore, the bonding adhesive used to bond the cannula to the hub istypically disposed within the hub protrusion. The adhesive is cured byexposure to ultraviolet (UV) radiation or by application of heat orchemical reaction from a two-part adhesive. Because the adhesive iswithin the hub protrusion, the UV radiation must pass through the hubwalls, which are typically made of polypropylene, to induce curing inthe adhesive. Thus, a lengthy curing time is required to cure theadhesive due to the UV radiation having to pass through the hub walls toirradiate the adhesive.

Drug delivery pens are also disclosed in U.S. Patent ApplicationPublication Nos. 2006/0229562 to Marsh et al. and 2007/0149924 to R.Marsh, the entire contents of both of which are hereby incorporated byreference.

Accordingly, a need exists for a hub protrusion having an increasedsurface area that contacts a patient's skin during an injection, therebyreducing the pressure exerted against the patient's skin during theinjection.

SUMMARY OF THE INVENTION

In accordance with an aspect of the present invention, a hub has anincreased surface area that contacts a patient's skin during aninjection to reduce the pressure exerted against the patient's skinduring the injection, thereby increasing the comfort of the patient.

In accordance with another aspect of the present invention, a bondingadhesive is disposed on an outer surface of the hub, thereby decreasingthe required curing time.

In accordance with another aspect of the present invention, the adhesiveis disposed on an outer surface of the hub to increase the contact areabetween the cannula adhesive and hub, thereby increasing the strength ofthe bond.

Objects, advantages, and salient features of the invention will becomeapparent from the following detailed description, which, taken inconjunction with the annexed drawings, discloses exemplary embodimentsof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above benefits and other advantages of the various embodiments ofthe present invention will be more apparent from the following detaileddescription of exemplary embodiments of the present invention and fromthe accompanying figures, in which:

FIG. 1 is a perspective view of an assembled existing drug delivery pen;

FIG. 2 is an exploded perspective view of the components of the drugdelivery pen of FIG. 1;

FIG. 3 is an exploded perspective view of a needle assembly for a drugdelivery pen;

FIG. 4 is a cross-sectional view of the pen needle hub assembly of FIG.3 in an as-manufactured state;

FIG. 5 is a perspective view of an existing hub for a pen needleassembly;

FIGS. 6A to 6C are perspective views of a hub for a pen needle assemblyaccording a first exemplary embodiment of the present invention;

FIG. 6D is a perspective view of a hub for a pen needle assemblyaccording to the first exemplary embodiment of the present invention andhaving additional adhesive spacing;

FIG. 7A is a perspective view of a hub for a pen needle assemblyaccording a second exemplary embodiment of the present invention;

FIG. 7B is a perspective view of a hub for a pen needle assemblyaccording to the second exemplary embodiment of the present inventionand having additional contours for angle injections;

FIGS. 8A and 8B are perspective views of a hub for a pen needle assemblyaccording a third exemplary embodiment of the present invention;

FIG. 8C is a cross-sectional view of a hub for a pen needle assemblyaccording to the third exemplary embodiment of the present invention;

FIGS. 9A and 9B are perspective views of a hub for a pen needle assemblyaccording a fourth exemplary embodiment of the present invention;

FIG. 9C is a cross-sectional view of a hub for a pen needle assemblyaccording to the fourth exemplary embodiment of the present invention;

FIG. 10A is a perspective view of a hub for a pen needle assemblyaccording to a fifth exemplary embodiment of the present invention; and

FIG. 10B is a cross-sectional view of a hub for a pen needle assemblyaccording to the fifth exemplary embodiment of the present invention.

Throughout the drawings, like reference numbers will be understood torefer to like parts, components and structures.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The following description and details of exemplary embodiments of thepresent invention, while generally disclosed in a typical drug deliverypen, as shown in FIGS. 1 and 2, could more broadly apply to a needle andhub assembly for use in conjunction with, or incorporated onto, otherinjection devices such as syringes, infusion devices and any otherneedle-containing devices in which such features are desirable.

In the exemplary embodiments of the present invention, a hub has anincreased surface area that contacts a patient's skin during aninjection to reduce the pressure exerted against the patient's skinduring the injection, thereby increasing the comfort of the patient.Additionally, the increased contact surface area provides a more stableinjection surface during injection, particularly when using cannulashaving shorter lengths.

A hub 151, as shown in FIGS. 6A-6C, has a substantially cylindrical body153. A projection, or protrusion, 155 extends outwardly from a distalend 154 of the body 153 of the hub 151. An opening 156 in the projection151 receives a cannula. The increased surface area at the distal end 158of the protrusion reduces the pressure exerted against a patient's skinduring cannula injection, thereby increasing the patient's comfort.Preferably, the hub 151 is made of plastic, such as polypropylene.

The adhesive for bonding the cannula to the hub 151 is disposed on theouter surface at the distal end 158 of the protrusion 155. The distalend 158 is preferably provided having a contour near its outercircumference that becomes substantially flat while approaching theinner portion 159. The inner portion 159 of the projection 151 slopesdownwardly toward the opening 156, thereby facilitating movement of theadhesive to the opening. A plurality of ribs 152 are disposed in theinner portion 159 that increase the contact surface area between theadhesive and the hub 151. When the adhesive is cured, the inner portion159 is substantially filled with the adhesive such that the distal end158 of the projection 155 is substantially flush. By disposing theadhesive on the outer surface of the protrusion 155, the UV radiationused to cure the adhesive does not have to pass through the hub walls toirradiate the adhesive. Thus, the curing time for the adhesive isdecreased. Furthermore, the contact area between the cannula adhesiveand the hub 151 is also increased, thereby increasing the bond strengthof the cannula adhesive with the hub 151. Corona, plasma or othersurface treatment may be used with this or any other embodiment toincrease the adhesive/hub bond strength.

FIGS. 6A and 6B are perspective views of a hub for a pen needle assemblyaccording to a first exemplary embodiment of the present invention, andFIG. 6C is a cross-sectional view of the hub of FIGS. 6A and 6B takenalong center line of a rib 152. The cross-sectional view of FIG. 6Cshows the inner threads 157 of the hub 151 and shows the opening 156extending through the distal end 158 for communication with an interiorof the hub 151. However, in yet other embodiments of the presentinvention, the opening 156 may be modified as shown in FIG. 6D.

FIG. 6D is a perspective view of a hub for a pen needle assemblyaccording to the first exemplary embodiment of the present invention andhaving additional adhesive spacing. Specifically, as shown in FIG. 6D,an opening 196 may be provided having one or more rings 193 or otherfeature to facilitate adhesive filling. These rings 193 may be used withany embodiment of the needle hub to improve the cannula/hub bondstrength. Furthermore, the entrance of the opening 196 may be providedwith a guide space or slope 191 by modifying the ribs 152 at a pointimmediately surrounding the opening 196. Such a guide space 191 mayfacilitate needle positioning by serving as a guide during assembly.

A hub 161, as shown in FIGS. 7A and 7B, has a substantially cylindricalbody 163. A protrusion 165 extends outwardly from a distal end 164 ofthe body 163 of the hub 161. An opening 166 in the protrusion 165receives a cannula. A plurality of projections 167 surround theprotrusion 165. The distal ends 168 of the plurality of projections 167form a substantially planar surface for contacting a patient's skinduring injection. The distal ends 168 of the plurality of projections167 are preferably flush with or extend beyond the distal end of theprotrusion 165. The increased surface area provided by the distal ends168 of the plurality of projections reduces the pressure exerted againsta patient's skin during cannula injection, thereby increasing thepatient's comfort. However, in yet other exemplary embodiments of thepresent invention, the distal ends of the plurality of projections 167may be modified as shown in FIG. 7B.

FIG. 7B is a perspective view of a hub for a pen needle assemblyaccording the second exemplary embodiment of the present invention andhaving additional contours for angle injections. In the exemplaryembodiment shown in FIG. 7B, distal end 169 of the plurality ofprojections 167 are contoured, rounded and/or provided with a shape andradius to facilitate injections that may occur or be attempted at anglesother than perpendicular to the skin surface, while maintaining thebenefit of the increased surface area provided by the distal ends of theplurality of projections.

A hub 171, as shown in FIGS. 8A-8C, has a substantially cylindrical body173. A protrusion 175 extends outwardly from a distal end 174 of thebody 173 of the hub 171. An opening 176 in the protrusion 175 receives acannula and frustoconical shaped recess 200 as shown in FIG. 8C. Asubstantially hemispherical projection 177 extends outwardly from planardistal face or shoulder 204 at the distal end 174 of the hub 171. Anopening 178 in the projection 177 is substantially flush with the distalend of the protrusion 175. The distal end 179 of the projection 177 is asubstantially flat planar annular shaped axial face with an annularouter edge 202 for contacting a patient's skin during injection. Thedistal end 179 of the projection 177 is preferably flush with or extendsbeyond the distal end of the protrusion 175 (FIG. 8C). The increasedsurface area provided by the distal end 179 of the projection 177reduces the pressure exerted against a patient's skin during cannulainjection, thereby increasing the patient's comfort. The recessed ring178 of the surface of the hub 171 may be used to facilitate attachmentof a cannula shield. The recessed ring on the surface of the hub mayalso be used to facilitate manufacturing of the pen needle assembly bycollecting adhesive that might overflow from the adhesive well at thecenter of the hub.

As shown in greater detail in FIG. 8C, the adhesive well 195 may beprovided at or near the end of the protrusion 175. Furthermore, as notedabove and more clearly shown in FIG. 8C, the distal end of theprojection 177 is preferably substantially flush with or extendsslightly beyond the distal end of the protrusion 175. Further, innerthreads of the hub 171 are shown.

A hub 181, as shown in FIGS. 9A-9C, has a substantially cylindrical body183. A protrusion 185 extends outwardly from a distal end 184 of thebody 183 of the hub 181. An opening 186 in the protrusion 185 receives acannula. A substantially spherical projection 187 extends outwardly fromthe distal end 184 of the hub 181. A distal surface 188 of theprojection 187 is substantially flush with a distal end 182 of theprotrusion 185. The distal surface 188 of the projection 187 issubstantially planar for contacting a patient's skin during injection.The distal surface 188 of the projection 187 is preferably flush with orextends beyond the distal end 182 of the protrusion 185. An innerportion 189 of the projection 187 slopes inwardly and downwardly towardthe protrusion 185 to form a valley, which is adapted to receive anothermember of the pen needle assembly, such as a shield. The increasedsurface area provided by the distal surface 188 of the projection 187reduces the pressure exerted against a patient's skin during cannulainjection, thereby increasing the patient's comfort.

As shown in greater detail in FIG. 9C, an adhesive well 197 may beprovided at or near the end of the protrusion 185. Further, innerthreads 199 of the hub 181 are shown.

A hub 1001, as shown in FIGS. 10A-10B, has a substantially cylindricalbody 1003. A protrusion 1005 extends outwardly from a distal end 1004 ofthe body 1003 of the hub 1001. An opening 1006 in the protrusion 1005receives a cannula. A substantially spherical projection 1007 extendsoutwardly from the distal end 1004 of the hub 1001. A distal surface1008 of the projection 1007 is substantially flush with a distal end ofthe protrusion 1005. The distal surface 1008 of the projection 1007 issubstantially planar for contacting a patient's skin during injection.The distal surface 1008 of the projection 1007 is preferably flush withor extends beyond the distal end of the protrusion 1005.

The exemplary embodiment shown in FIG. 10A is formed having twoconcentric wells 1010 and 1020, with the inner well 1010 provided tocapture excess adhesive and the outer well 1020 provided to receive andsecure a shield, but are not limited thereto.

As shown in greater detail in FIG. 10B, an adhesive well 1012 may beprovided at or near the end of the protrusion 1005. The adhesive well1012 facilitates visual inspection of the amount of adhesive in the wellby using a single top view inspection camera. The more adhesive in thewell, the wider the circle of adhesive that is visible in a top-downview. Current inspection methods overfill the glue well and look forglue overflowing the hub protrusion. Further, inner threads 1014 of thehub 1001 are shown.

The foregoing embodiments and advantages are merely exemplary and arenot to be construed as limiting the scope of the present invention. Thedescription of exemplary embodiments of the present invention isintended to be illustrative, and not to limit the scope of the presentinvention. Various modifications, alternatives and variations will beapparent to those of ordinary skill in the art, and are intended to fallwithin the scope of the invention, as defined in the appended claims.

What is claimed is:
 1. A hub assembly for an injection apparatus,comprising: a body having a first end and a second end, said firstdistal end having forming a shoulder extending radially inward from anouter edge of said first end of said body; an inner protrusion extendingaxially outward from said first end of said body, said inner protrusionhaving a continuous substantially flat, planar annular-shaped axial facewith an outer annular edge, an outer radial surface and an inner radialsurface, and a plurality of axially extending ribs on said outer radialsurface; an outer projection extending axially outwardly from saidshoulder and said first end of said body, said outer projection having asubstantially flat planar axial face, and a continuous substantiallyhemispherical outer surface extending between said shoulder of saidfirst distal end of said body and an outer annular edge of said flat,planar annular-shaped axial face of said outer projection; said bodyhaving an opening extending axially between said second end of said bodyand said axial face of said inner protrusion, said opening having aninclined, frustoconical shaped well at said axial face of said innerprotrusion configured for receiving an adhesive for attaching a cannulain said opening.
 2. The hub assembly for an injection apparatusaccording to claim 1, wherein a plurality of rings are formed in saidopening in said body to facilitate receipt of the adhesive.
 3. The hubassembly for an injection apparatus according to claim 1, wherein saidcontinuous axial face of said inner protrusion is substantially flushwith said axial face of said outer projection.
 4. The hub assembly foran injection apparatus according to claim 1, wherein said axial face ofsaid inner protrusion and said axial face of said outer protrusion areconfigured to facilitate injections substantially perpendicular to askin surface.
 5. The hub assembly for an injection apparatus accordingto claim 1, wherein said outer projection is spaced radially outwardfrom said inner protrusion to define an annular recess between saidouter projection and said inner protrusion.
 6. The hub assembly for aninjection apparatus according to claim 1, wherein said ribs on saidinner protrusion project from said from said outer annular surface ofsaid inner protrusion toward an inner annular surface of said outerprojection.
 7. The hub assembly for an injection apparatus according toclaim 6, wherein said axially extending ribs have an inclined top edgeconverging inward and terminating at an outer annular edge of said innerprotrusion.
 8. The hub assembly of according to claim 1, wherein saidaxial face of said inner protrusion is recessed with respect to saidaxial face of said outer projection.
 9. A hub assembly for an injectionapparatus, comprising: a body having a first axial distal end with asubstantially planar distal face extending radially inward from an outerannular edge of said body; an inner protrusion extending axiallyoutwardly from said first axial end of said body and having asubstantially flat distal end, said distal end of said inner protrusiondefining an annular axial face, said axial face being substantiallyplanar, continuous and equidistant from said first axial end of saidbody; an opening in said inner protrusion configured to receive acannula, said opening extending from an interior of said body to saidaxial face of said inner protrusion and having an outer edge at saidaxial face with a first dimension, a passage extending through said bodyand having a second dimension for receiving the cannula, and an inclinedfrustoconical surface extending between an inner annular edge of saidaxial face of said inner protrusion and said passage; and an outerprojection spaced outwardly from and circumferentially surrounding saidinner protrusion, said outer projection having a substantially flatplanar axial face to form a distal end of said outer projection havingan increased surface area relative to said axial face of said innerprotrusion, thereby reducing the pressure exerted against a patient'sskin during an injection, and said outer projection having asubstantially hemispherical shaped outer surface defining a continuouscurved outer surface extending between said substantially flat planaraxial face of said outer projection and said distal face at said firstdistal end of said body.
 10. The hub assembly for an injection apparatusaccording to claim 9, wherein an annular recess is formed between saidouter projection and said inner protrusion.
 11. The hub assembly for aninjection apparatus according to claim 9, wherein the flat planar distalface of said outer projection is equidistant from said first axial endof said body to facilitate contacting the patient's skin during theinjection.
 12. The hub assembly for an injection apparatus according toclaim 9, wherein said outer projection is spaced inwardly from an outeredge of said first end of said body.
 13. The hub assembly for aninjection apparatus according to claim 9, wherein an outer annularsurface of said inner protrusion has a plurality of outwardly extendingribs extending toward an inner annular surface of said outer projection,and where said ribs have an inclined top end converging toward andterminating at an outer edge of said axial face of said innerprotrusion.
 14. The hub assembly for an injection apparatus according toclaim 13, wherein said annular axial face of said inner protrusion issubstantially flat and oriented in a plane of said axial face of saidouter projection.